wxMac, PaintEvent

[Nusret Taşçı]

> wxPanels are windows, not just drawable areas, so yes, you will have to
> connect the events in another way, or call back upon the parent from the
> paint events of the chilrdren. 

I'm sorry that I answer so late, but I couldn't continue fixing the 
remaining problem until today.

I've tracked down the issue to one specific point, let me give an 
example so that we both have something to argue about:

#include "wx/wxprec.h"
#ifndef WX_PRECOMP
     #include "wx/wx.h"
#endif
// Define a new application type, each program should derive a class 
from wxApp
class MyApp : public wxApp
{
public:
     virtual bool OnInit();
};

// Define a new frame type: this is going to be our main frame
class MyFrame : public wxFrame
{
public:
     MyFrame(const wxString& title);
private:
     void ButtonClicked(wxCommandEvent &event);
     void UpperPaint(wxPaintEvent &event);
     void LowerPaint(wxPaintEvent &event);

     bool     m_bDrawUpperRed;
     wxButton *pButton;
     wxPanel  *pUpperPanel;
     wxPanel  *pLowerPanel;
     DECLARE_EVENT_TABLE()
};

BEGIN_EVENT_TABLE(MyFrame, wxFrame)
END_EVENT_TABLE()

IMPLEMENT_APP(MyApp)

bool MyApp::OnInit()
{
     if ( !wxApp::OnInit() )
         return false;
     MyFrame *frame = new MyFrame(_T("Minimal wxWidgets App"));
     frame->Show(true);
     return true;
}

MyFrame::MyFrame(const wxString& title)
        : wxFrame(NULL, wxID_ANY, title)
{
     m_bDrawUpperRed = false;
     pButton = new wxButton(this, wxID_ANY, wxT("Change Color"));
     pUpperPanel  = new wxPanel(this, wxID_ANY, wxPoint(100, 0), 
wxSize(100, 100));
     pLowerPanel  = new wxPanel(this, wxID_ANY, wxPoint(100, 100), 
wxSize(100, 100));
     pButton->Connect(wxEVT_COMMAND_BUTTON_CLICKED, 
wxCommandEventHandler(MyFrame::ButtonClicked), NULL, this);
     // POI
     pUpperPanel->Connect(wxEVT_PAINT, 
wxPaintEventHandler(MyFrame::UpperPaint), NULL, this);
     pLowerPanel->Connect(wxEVT_PAINT, 
wxPaintEventHandler(MyFrame::LowerPaint), NULL, this);
}

void MyFrame::ButtonClicked(wxCommandEvent &)
{
     m_bDrawUpperRed = !m_bDrawUpperRed;
#if 1 // POINT OF INTEREST
     // case 1
     pUpperPanel->Refresh();
     pLowerPanel->Refresh();
#else
     //case 2
     Refresh();
#endif
}

void MyFrame::UpperPaint(wxPaintEvent &event)
{
     wxPaintDC dc((wxWindow*)event.GetEventObject());
     if (m_bDrawUpperRed)
         dc.SetBackground(*wxRED);
     else
         dc.SetBackground(*wxGREEN);
     dc.Clear();
}

void MyFrame::LowerPaint(wxPaintEvent &event)
{
     wxPaintDC dc((wxWindow*)event.GetEventObject());
     if (m_bDrawUpperRed)
         dc.SetBackground(*wxGREEN);
     else
         dc.SetBackground(*wxRED);
     dc.Clear();
}

This sample works.
If you change the connects to somethink like following:
     // POI
     pUpperPanel->Connect(pUpperPanel->GetId(), wxEVT_PAINT, 
wxPaintEventHandler(MyFrame::UpperPaint), NULL, this);
     pLowerPanel->Connect(pLowerPanel->GetId(), wxEVT_PAINT, 
wxPaintEventHandler(MyFrame::LowerPaint), NULL, this);

than it will not work anymore. The difference is "->GetId()". When 
connecting to a painthandler, this seems not to work for wxMac. However, 
Connecting with GetId() for other handlers seem to work, though I 
haven't tested all of them of course.


Nusi